Crankcase for multiple bank radial motors



Dec. 3, 1940. F. BRANDNER CRANKCASE FOR MULTIPLE BANK RADIAL MOTORS Filed Sept. 6, 1938 2 Sheets$heet 1 Dec. 3, 1940. F. BRANDNER CRANKGASE FOR MULTIPLE BANK RADIAL MOTORS 2 Sheets-Sheet 2 Filed Sept. 6, 1938 @mm 76 V 7 d z s M V w 6 M 9 7 9 u 5 I 7 4 c c J I k w m 0 i aw G W i M Q 2 6 m m. .9 7 2. m H E im. G b b H| G 4 m 5 6 4 v w I a a a Q 5 3 7 a 2 m. 4 4 w E .h

Patented pec. 3, 1.940

CRANKCASE FOR MULTIPLE BANK, RADIAL,

MOTORS Ferdinand Brandner, Dessau, Germany, assignor to Junkers Flugzeug-und-Motorenwerke Aktiengesellschaft, Dessau, Germany, a corpora tion of Germany Application September 6, 1938, Serial No. 228,47

Germany September 6, 1937 8 Claims. (Cl. 123-45) This invention relates to improvements in crankcases'for multiple bank radial motors which are primarily adapted for use on airplanes.

It is'an object of the invention to provide a 6 crank whereon all the cylinders are supported so that the case and the cylinders together form a thoroughly rigid unit which will, without perceptible distortion, withstand all the stresses to which it is subjected when the motor is in operation; and wherein the weight of the motor and the said stresses are transferred to the airplane fuselage or other support on which 'the motor is mounted.

I am aware that crankcases for multiple bank radial motors have already been made which were split, either transversely Of the crank shaft axis or in alignment therewith. In both cases however, satisfactory utilization of these forms of construction has been limited to motors hav- 20 ing only quite a small number of cylinders, primarily because no satisfactory way has been found to make such crankcases carrying a greater number of cylinders sufficiently rigid within permissible weight limits. Another'object of the invention is then to provide a crankcase for multiple bank radial motors which is split,.longitudinally parallel with the crank shaft axis and a spaced vertical distance therefrom, and consists of a larger substantially U-shaped portion and a smaller portion; wherein most of the cylinders are carried by the larger portion and the remainder byv the smaller portion; and wherein the two crankcase portions are .5 so secured to one another that no perceptible movement of one portion relative to the other occurs even in motors having a large number of banks. a I

Further objects of the invention are to provide 40 a crankcase for multiple bank radial motors: which is relatively simple to manufacture and assemble, and light in weight; wherein a crank shaftand its connecting rods may be quickly and easily installed or removed; and wherein the crankcase and the radially disposed cylinders form a structure which is tubular-in cross section thereby adding to its rigidity.

Having thus briefly stated some of the major objects and advantages of the invention, I will now proceed to describe two preferred embodiments of the invention withthe aid of the accompanying drawings, in which:

Figure l is a cross section on the line l--l of Figure 2, showing a crankcase for multiple bank radial motors having radially disposed cylinders in each bank.

Figure 2 is a longitudinal section on the line both the number of banks and the number of cylinders in each bank are subject to considerable variation. All the cylinders of all the banks are carried by a common crankcase 1 which is.

tubular in cross section and split longitudinally along a joint 8 parallel with. the axis of the crank shaft bearings l5 and spaced 8. vertical distance a therefrom, thereby forming a larger portion Ia, which is substantially U-shaped in cross.-

section, and a smaller portion lb. The cylinders l, 2, 3 and 4 of all the banks are carried by the larger portion la and the remaining cylin ders 5 and 6 of all the banks by the smaller portion 1b. Thetwo crankcase portions la and lb;

are secured to one another by suitable fastening means such as the bolts 9,. and are reinforced at right angles to the said crank shaft bearing axis by walls Ill and II respectively formed integral with their respective portions.

Formed integral with the larger crankcase ortions la are a plurality of crank shaft bearings I! having laterally opposed guides I I! between whlch covers II are inserted. l8 denotes studs in threaded engagement with the bearings l5 which pass through the covers l1 and have nuts "a on their outer extremities by which the said covers are securely held in position. Extending transversely through each pair of guides l6 and through the cover I! between them is a draw bolt I! which performs a dual function; it both acts as a dowel to prevent substantially radial movement of the cover II and also forces the guides it towards one another into intimate contact with the adjacent lateral faces of the said cover, thereby reinforcing the structure and providing a, thoroughly rigid bearing. The latter point is of prime importance because th provision of a crankcase of utmost rigidity is a necessity for the successful operation of this type of motor. in this connection it may slso be re-- marked that the tops of the bearings l1 lie sub="""" stantially in line with the joint 8,, so that the inner edge faces of the ribs ll may be slightly spaced from the coverswithout weakening the 5 said ribs or reducing the strength of the assembled structure. It will also be seen that the smaller crankcase portion lb and the bearing covers I! may be readily removed so that a crank shaft (not shown) mounted or to be mounted in with one cylinder in every other bank, and each I row of cylinders thus constituted, for instance the' cylinders 3a, 3b, 5c and 3:1, is parallel to the axis of the crank shaft bearing I5. Again each of the rows of cylinders is preferably formed in a single block to increase the strength of the struc-v ture. I

Formed integral with the larger crankcase .portlon la and extending longitudinally thereof are a plurality of water jackets 26, 21, 28 and 29 radially disposed to the crank shaft bearing i5.

Each of these water jackets supports one cylinder of each bank,-. for instance, as may be seen in Figure 2, the cylinders an; 3b, 3'0 and 3d are'all carried by the water jacket 28. water jackets 30 and 5| are each integral with the 30 smaller crankcase portion lb, and each carries one cyilnderfof each bank as shown in the aforesaid view wherein the cylinders 5a, 5b, 5c and 5d are carried by;the'jacket 30. It is of course understood that the cylinders l, 2, 3, 6, 5 and 6 are made integral with their respective -water jackets 26, 21, 28, 29, 3D, and 39 which are fre- 'quently cast around them, though .any other preferred means of obtaining absolutely rigid connections between the water jackets and the cylin- 40 ders supported by them may be employed when desired. 32. denote radial ribs which extend between A and are integral with adjacent pairs of water jackets 28, 21, 28 and 2'9, and 3e and 35, upon the larger and smaller crankcase portions la and lb respectively. 20, 2l,'22, 23, 2E and 25 indicate cylinder heads upon the cylinders l, 2, 3, 8, 5 and 6 respectively.

Figure 3 illustrates a cross sectional view of a modified arrangement of the invention wherein a plurality of banks of nine radially disposed cyllinders are employed. The crankcase 38, which is also of tubular cross section, again consists of a larger portion dim and a smaller portion 35b joined to one another in a plane parallel to the axis of the crank shaft bearings 55andspaced a vertical distance a therefrom. I

In this case the cylinders M, 32, 63, H3, and

56 of all the banks are carried by and integral eowlth the larger crankcase portion Elia which is again U-shaped in section, and the remaining cylinders 41, wand 49 are carried by and in-' tegral with the smaller portion 40b. Between I adjacent radial pairs of cylinders on both hous- 65 ing portions spaced inner and outervwalls 40c and 4011 are provided which extend lengthwise lof the crankcase andcomplete the tubular cross sectional form. These, walls not only reinforce the structure and further increase itsrigidity ,but also provide passages 5 9 between them which extend longitudinally of the crankcase and may be utilized as pipe. conduits orfor any other pufpose; V I t .D

Mounted upon the crank shaft bearings '55,

' which are integral with thelarger crankcase por- Similarly .the

"tion Illa, are covers 54 transversely, across the tops of which contact surfaces 53 are provided. Formed integral with the smaller crankcase" portion lllb are a plurality of transverse walls 50 which project inwardly and terminate in ribs 5 5| across the edge faces of which contact surfaces'52 are formed to bear against the said surfaces'53. Studs 55, which project from the bearings 55 extend through the covers '54 and also through pillars 50a formed upon opposite edges 10 of the walls 50. Nuts 5'l threaded upon the studs 55 intermediately of their height hold the covas 54 in position, and nuts 58 uponthe outer extremities of, the said studs-bear against the ends of the pillars 50a and force the contact 15 surfaces 52 into intimate contact with the contact surfaces 53.

The transverse walls 50 are also provided with laterally opposed padsfil which are in alignmerit with opposed pairs of bearing cover guides 20 55 integral with the larger crankcase portion 40a.

These pads extend between steps 62 formed upon the outer portion of the larger crankcase portion 40a and opposed faces 53 of the adjacent guides 55. Extending through the steps 62, the 25 pads 5|, the guides 65 and the covers 54' are aligned passages 54 through which draw bolts 55 project, and press all these parts firmly to-' gether. The draw bolts 66 are disposed transversely of the axis of the bearings 55 and also at right angles to the vbolts 9 which extend through the joint of the two crankcase portions and hold the said portions together.

Whilein the foregoing two constructions of my invention have been described and shown, it 35 is understood that the invention is susceptible to such further alterations andmodifications as i fall within the scope of the appended claims;

WhatI claim is:

1. A crankcase arrangement for multiple bank 4;; radial 'motors comprising a crankcase having crankshaft bearings integral therewith, said case being split parallel with the bearingaxis a spaced vertical distance therefrom whereby said case is divided into a larger and asmaller portion. 45 means securing said portions to one another; all said bearingsbeing integral with the larger por- H tion,- opposed guides on said bearings, a *cover mounted on each bearing'between the opposed guides, .bolts extending through each opposed gg pair of guides and the-cover between them holding said parts immovable, and banks of radially disposed cylinders carried by the crankcase.

2. A crankcase arrangement, for multiple bank radial motors, comprising a tubular crankcase 55 having crank shaft bearings integral therewith, said case beingsplitparallel with the bearing axis aspaced vertical 'distance therefrom thel'B". by dividing the case into a larger portion with which all the bearings are integral and a smaller as portion, laterally opposed guides. on eachbearing, a cover on each bearing between each 0p posed pairi'of guides, a transverse wall on said smaller'portion extending across each bearing, said walls having laterally opposed pads thereon 65 extending between the tubular wall bf the'large'r crankcase portion and theadjacent guides, and 1 fastening means extending through the tubular 'wall,'pads, guides and covers whereby the two crankcase portions and the bearing covers; are 70 held in'un'ovable, and banks of cylinders radially di'sposed on said crankcase A 3. Iii a crankcase arrangement for multiple bank'r'adial n'iotors, the combinationset forth in claim 2, wherein the inner" edge facesfof; the'lli case being split parallel with the bearing axis a spaced vertical distance therefrom whereby said case is divided into a larger and a smaller portion, means securing the portions to one another, all said bearings being integral with the larger case portion, covers mounted on the bearings, inwardly projecting transverse walls integral with the smaller case portion extending substantially the full depth thereof across said covers at right angles to the bearing axis, the inner edge faces of the transverse walls bearing upon said covers and the tops of said covers being substantially in alignment with the joint between the crankcase portions, and means holding said inner edge faces securely against said covers.

5. A crankcase arrangement for multiple bank radial motors comprising a crankcase having crank shaft bearings integral therewith, said case being split parallel with the bearing axis a spaced vertical distance therefrom whereby said case is divided into a larger and a smaller portion, means securing the portions to one another, all said bearings being integral with the larger case portion, covers mounted on the bearings, in-

wardly projecting transverse walls integral with a the smaller case portion extending substantially the full depth thereof across said covers at right angles to the bearing axis, the tops of said covers being substantially in alignment with the joint between the crankcase portions, and fastening means engaging the bearings and extending through said covers and transverse walls to hold the former upon the bearings and the edge faces of the latter upon the covers.

6. A crankcase arrangement for multiple bank radial motors comprising a; crankcase having crank shaft bearings integral therewith, said case being split parallel with the bearing axis a spaced vertical distance therefrom whereby said case is divided into a larger and a smaller portion, means securing the portions to one another, all

said bearings being integral with the larger case portion, covers mounted on the bearings, inwardly projecting transverse walls integral with the smaller case portion extending substantially the full depth thereof across said covers at right angles to the bearing axis, the tops of said covers being substantially in alignment with the joint between the crankcase portions, studs extending from the bearings through the covers and transverse walls, nuts upon said studs intermediate their length securing the covers on the bearings, and nuts upon the outer extremities of the studs holding the edge faces of the transverse walls in contact with the tops of the covers,

7. A crankcase arrangement for multiple bank radial motors, comprising a tubular crankcase having crank shaft bearings integral therewith, said case being split parallel with the bearing axis to thereby divide it into a larger portion and a smaller portion, laterally opposed guides on each bearing, a cover on each bearing between each opposed pair of guides, a transverse wall on said smaller portion extending across each bearing, said walls having laterally opposed pads thereon extending between the tubular wall of the larger crankcase portion and the adjacent guides, and fastening means extending through the tubular wall, pads, guides and covers whereby the two crankcase portions and the bearing covers are held immovable, and banks of cylinders radially disposed on said crankcase.

8. In a crankcase arrangement for multiple bank radial motors, the combination set forth in claim '7 wherein the inner edge faces of the transverse walls between the pads bear upon said covers, and means holding said edge faces in firm engagement therewith.

FERDINAND BRANDNE'R. 

